Feeding mechanism for fastener driving devices



FEEDING MECHANISM FOR FASTENER DRIVING DEVICES Filed Oct. 9, 1957 L. R. CAMPBELL Jan. 3, 1961 2 Sheets-Sheet 1 INVENTOR.

162' R. CHM/ 854A.

BY %,M 1

ATTORNEYS Jan. 3,1961 L R. CAMPBELL 2,966,681

FEEDING MECHANISM FOR FASTENER DRIVING DEVICES Filed Oct. 9, 1957 2 Sheets-Sheet 2 INVENTOR.

L f! A", 679011 854 L 2,666,661 V Patented Jan. 3, 1961 FEEDING MECHANISM FOR F ASTENER DRIVING DEVICES Lee R. Campbell, 1921 Kenneth Ave., Royal Oak, Mich.

Filed Oct. 9, 1957, Ser. No. 689,153

Claims. (Cl. 1-44.4)

This invention relates to improvements in structures fior feeding successive fasteners into position for engagement by a driving element forming part of a fastener driving device. These improvements of the invention are particularly adapted for use with staple driving devices and will be described in their application to a pneumatically operated staple driving gun.

All staple driving devices conventionally include a driving member and some means for reciprocating it in a guideway. In a pneumatically operated gun these means consist of a cylinder and piston which when actuated operate the driving member on a driving stroke. is usually employed to move the driving member and piston on a return stroke. Some form of magazine is provided for holding a number of staples and successively feeding them into the guideway for engagement by the driving member on its driving stroke. Conventionally, the magazine supports the supply of staples for movement in a path perpendicular to the path of movement of the driving member although in some cases a magazine has been employed where the staples move along a path which gradually curves to intersect the path of movement of the drive at a right angle.

The improvements of the invention permit the construction of a magazine wherein the path of movement of staples of the driving position includes a portion that is relatively abruptly curved so that the main storage portion of the magazine can be arranged at less than a right angle to the path of movement of the driving member. In the preferred form of construction the main storage portion of the magazine extends parallel to the path of driver movement, thus resulting in a staple driving device which is very compact in its dimension normal to the path of driver movement. At the same time, the storage section of the magazine can be made to have a capacity which is relatively much greater than possible with conventional constructions.

In its entirety, the invention consists of a magazine having a track member on which a number of staples can be slidably mounted in end to end relation. The discharge end of this track member feeds into the path of movement of a staple driving member and is mounted in fixed relation thereto. At a location preferably near the discharge end, the track member curves relatively abruptly and extends into a storage section which can be of any length desired. A track guide is mounted in spaced parallel relation with the track to provide a path for the free movement of staples between the track and track guide. Means are included for normally urging staples along the path so defined toward the discharge end of the track. That portion of the track guide adjacent the discharge end of the track and adjacent the curved portion of the track is movable toward the track and means are included for imparting such movement to the track guide in synchronism with each driving stroke of the staple driving member. This movement of the track guide forces it into engagement with staples supported on the track;

' Preferablythe magazine construction includes a second,

A spring.

movable member, hereinafter termed a breaker, which is brought into engagement with at least one staple supported on the track at the abruptly curved portion thereof and means are included for producing such movement of this breaker member also in synchronism with driving movement of the staple driving member.

The discharge end of the track guide projects slightly into the guideway for the staple driver. Each time the driver is actuated on its driving stroke the projecting end of the track guide is retracted from the driver guideway as the track guide is moved into engagement with staples supported on the track. This retracting and staple en-' gaging movement of the track guide interrupts normal movement of the staples into discharge position, rearranges staples in a perfect row on the staple track, and prevents jamming between the staple driver and the last staple on the track.

Movement of the breaker member serves to break the adhesive bond between adjacent staples of a clip so that each staple can freely transverse the abruptly curved portion of the track. Preferably engagement between this breaker member and a staple takes place just as that staple is entering the curved track portion.

In pneumatically operated tools the means for moving the track guide and the breaker member consists of an auxiliary piston whose actuation is controlled in response toactuation of the main driving piston.

The improved construction generally results in the important features of positive intermittent feeding motion of staples into driving position, positive staple repositioning in the magazine during each driving stroke and at least partial separation of the adhesive bond between ad jacent staples of a clip. The advantages of the invention will be more fully described by explanation of the construction of the representative embodiments disclosed in the accompanying drawings which consists of the following views:

Fig. 1, a side elevation partly in section showing a pneumatic type of staple driving tool having the improved magazine of the invention;

Fig. 2, an elevation of the nose portion of Fig. 1 showing the position of staples along the track of the magazine;

Fig. 3, an enlarged sectional view taken along the line 3-3 of Fig. 1;

Fig. 4, a view similar to Fig. 2 but showing an alternate arrangement of the magazine relative the remaining portion of the tool; and F Fig. 5, a sectional detail taken on the line 55 of Referring to Figs. 1 to 3, the driving tool illustrated includes a cylinder 11, an air line 12 and a valve 13 for admitting air from the chamber 14 to the head of a piston 15. A staple driver 16 and a retaining member 18 enstorage portion 28 shown as indefinite in length and an abruptly curved portion 29 leading from the the storage portion 28 toward the discharge end 27. This track is secured to the nose portion 24 of the gun by a U-shaped bracket 30 which straddles the track and is secured thereto by a screw 31. The ends '32 of the bracket 30 are engaged to the nose portion 24. A second bracket 34 has a portion 35 which encircles the air chamber 14 and an L-shaped portion 36 which is secured to the trackby the screw 37 and which extends alongside the track in spaced relation therewith.

26 ata distance great enoughtoleave a clearance 41- for free sliding movement of staples 42 (Fig. 2) along the track which they straddle as can be seen in Fig. 3. Some means such as the weight 43 (Fig. 2) is preferably used to normally urgethe staples 42 toward the discharge end of the track. The: weight 43 is mounted on a bracket 43a which slidably engages three sides of the track portion 28 and is mounted on the track in the guideway 41 in opposite relation to the track supporting bracket 34 so as to be in clearance relation therewith.

The track guide 40 is connected to the bracket 34 by a screw 44. Between this screw 44 and the discharge and 46 of the track guide is a portion 45 thereof which is not restrained against movement toward the track but is urged toward a normal clearance relation therewith, as shown by the relative position of the parts in Fig. 1, by

the inherent resiliency of the material employed for thetr ack guide.

Portion 45 of the track guide is located against movethem away from the track by an adjustable stop 48 which is threaded into the nose portion 24 of the gun, is accessible through a hole 49 in the guideway 22 and is held in position by a set screw 56} (Fig. 3). Thus, track guide portion 45 is free to flex about screw 44 within limits defined by the stop 48 and the track 26.

A breaker member 52 is secured to the track guide 40 at 53. Breaker member 52 is resilient, is U-shaped in section (Fig. 3), and extends so that its free end 54 lies adjacent to the beginning of the curved portion 29 of the track.

- An auxiliary piston 56 is mounted in a cylindrical portion 57 formed on the nose section of the gun. The outer end of this piston 56 directly contacts breaker member 52. A passage 58 is formed in the side wall of the gun and communicates with ports 59 formed in the wall of the main cylinder 11 thereof and an opening 60 leading to the cylindrical portion 57.

Thus when valve 13 is actuated to admit air to the main cylinder 11 and cause piston 15 and driver 16 to move on a driving stroke, ports 59 are opened to air pressure during the travel of the piston 15 on this driving stroke. Air pressure is then supplied through the passage 58 to the auxiliary piston 56 forcing it into engagement with the breaker member 52 and the breaker member into engagement with the track guide portion 45 to produce flexing of the track guide 45 toward the track 26.

As shown in Fig. 2, this movement of the breaker member 52 forces its end 54 against the crown of a staple 62 forcing this staple firmly against the track 26 just at that portion thereof where the track changes direction to enter the curved track portion 29. Simultaneously with this movement of the breaker member 52 the track guide portion 45 is moved by piston 56 into contact with several of the staples on the track 26. Feeding movement of the staples is thus arrested, their end to end position is realigned, and the staple 62 engaged by the end of the breaker member 52- is separated from a following staple 64. If the two staples 62 and 64 form part of the same staple clip and are joined by an adhesive bond, as is commonly the case, this bond is broken at least along the leg portions of the two staples.

When air pressure to the main cylinder 11 is released the spring 20 will return the piston 15, driver 16 and driver retainer 18 to normal position. Air pressure on the auxiliary piston 56 will be simultaneously released and this piston will be returned to normal position by the resiliency in portion 45 of the track guide and in the breaker member 52.

The end 46 of the track guide is preferably tapered as shown in Fig. 1 and the dimensioning of this memberand setting of the adjusting screw 48 is such that the tapered end 46 of the track guide normally projects slightly into the driver guideway 22 as shown. During a driving stroke the end 46 of the track guide will be retracted from the driver guideway. On a. return stroke of the move-back into the driver guideway, at least as far-aspos sible until the driver has returned to a non-interfering position. This feature positively prevents the gun from becoming jammed by the driver blade pulling a staple into the guideway during its return movement. This feature also insures that the driver blade will engage the head of but one staple on each driving stroke.

Fig. 4 illustrates a slight variation on the configuration of the staple track. In this construction the storage portion 280 of the track extends at less than a right angle to the discharge portion 27 thereof. The remaining parts of the construction are identical and are identified by the same reference numerals as previously used except that an intermediate link 68 is used to translate movement of the auxiliary piston 56 to the breaker member 52 and track guide portion 45. This link is pivoted between a clevis 69 on the piston 56 and a second clevis 76 secured to the breaker'member.

Fig. 4 gives some indication of the flexibility possible in the configuration of the magazine and in its relation to the path of driver movement, particularly with respect to. the storage portion of the magazine which occupies the most space.

Operation of the staple driving tool is as follows: The magazine is loaded with a number of staples 42 which initially are forced along the guideway 41 so that the first staple to be driven is pushed into the driver guideway 22 and then the weight 43 is mounted on the track member 26 to normally urge all staples towards the driver guideway. In accordance with ordinary practice employed in staple driving tools, dimensioning of each individual staple is such as to produce frictional engagement between the staple and the driver guideway so that a staple in position to be driven does not fall out of the nose portion of the gun. When it is desired to drive a staple air pressure is admitted to the cylinder through operation of the valve 13 which is of the type illustrated in applicants co p'ending application Serial No. 682,823, filed September 9, 1957. Piston 15 is forced downwardly causing the driver blade 16 to slide by the tapered end 46 of the track guide 46 and engage the crown of the staple positioned in the driver guideway thereby advancing this staple is the guideway and out of the nose portion of the gun.

As previously mentioned, the track guide lower portion 41 is free to flex about the screw 44, and is set by the screw 48 so that the track guide nose portion 46 normally projects slightly into the driver guideway an amount just enough to give light contact between the end of the nose portion 46 and the side of driver blade when the driver blade moves downwardly. When this contact is established by the driver blade sliding by the tapered end 46 of the track guide, the track guide is moved slightly toward the track 26, taking up some of the clearance (see Fig. 2) between the track guide and the crowns of staples supported on the track, particularly at the curved portion 29 thereof. The amount of this track guide movement is not enough to take up all such clearance and hence the contact between the driver blade and end of the track guide offers very little resistance to driver blade movement. Toward the end of the driving stroke the ports 59 are opened to air pressure resulting in piston 56 being moved along a driving stroke. Piston 56 forces the breaker member into engagement with the track guide portion 45 and moves both the breaker member and track guide portion into contact with staples located in the guideway. The end 54 of the breaker member 52 is moved into engagement with the crown of the staple 62 which overlies the track 26 on the initial part of the curved portion 29 thereof, or in other words, where the first change in track direction takes place. This forces the crown of the staple 62 againstthe straight track portion 28. Contact between the end 54 of the breaker member 52 and the staple 62 is followed and augmented by contact of the track guide 40 with a plurality of staples occupying the curved portion 29 of the track. This positions the legs of staples contacted normal to the portion of the track on which they are supported and separates the legs of each staple contacted from those of an adjacent staple. In some instances engagement of the staples by the track guide will alone be sufficient to break the bond between adjacent staples so that they may properly traverse the curved portion 29 of the track. However, it has been found that particularly with heavy duty industrial type of staples the normal bond between adjacent staples is sufficiently strong so that proper separation of adjacent staples is not obtained when they are engaged by the track guide alone. This is due to the fact that the radius of the curved portion of the track guide is not the same as that of the curved portion 29 of the track and also due to the fact that the track guide does not move into contact with the curved track portion 29 along a line radial thereto. Movement of the track guide into contact with staples on the track does positively interrupt their feeding movement and reduces the normal clearance between the track and track guide. This results in. the staples being positively and properly positioned on the track.

When air pressure is released by operation of the valve 13 auxiliary piston 56 is moved on a return stroke by the resiliency of the track guide portion 45 and of the breaker member 52, and main piston 15 is moved on a return stroke by the spring 20. The action of the weight 43 then causes the row of staples to advance along the track 26 placing a new staple in position to be driven.

The construction disclosed and described has the following advantages:

(a) The prevention of a staple becoming jammed in the staple driving track especially during return movement of the staple driver after a driving stroke.

(b) The obtaining of an intermittent feeding movement of staples along the track of a staple magazine.

(0) A positive repositioning of staples on the track of the staple magazine with each driving stroke of the driver.

(d) A staple magazine having a track which includes a portion formed on a relatively short radius permitting the main storage portion of the track to extend at less than a right angle to the path of movement of the staple driver. In preferred forms of the invention the main storage portion ofthe staple track runs parallel to the path of driver movement resulting in a gun and track assembly which is extremely compact and which provides a staple magazine of greatly increased capacity as compared with conventional magazines where the track extends perpendicular to the path of driver movement.

(e) The separation in the magazine of each staple from the following staple of a clip, at least partially, so that each staple can be individually positioned to properly transverse the curved portion of the track referred to above.

(1) The synchronizing of the above advantages of intermittent feeding, staple re-positioning and staple separation with the operation of the stapler driver.

This particular construction has been found very useful for stapling machines of the type where a number of guns such as the one disclosed are mounted in a cluster to simultaneously drive a pattern of staples into a work piece. The guns can be mounted very close together because of the magazine construction. At the same time, the magazine capacity is far in excess of anything obtainable with other known types of construction.

It is recognized that many modifications of the particular construction disclosed may be necessary and desirable to adapt the invention to uses other than the par ticular use mentioned above. It is also recognized that it may be desirable to only utilize a portion of the ad- 6. vantages listed above and that this may readily be ac,- complished by the proper selection of certain of the structural features described or their equivalent. The scope of the invention is defined in the following claims.

I claim:

1. In a device for driving fasteners having a driver operable on driving and return strokes, means for feeding a fastening device into the path of movement of the driver for engagement thereby on each driving stroke comprising a track for slidably supporting a plurality of fastening devices, said track having a discharge portion leading into the path of movement of the driver at approximately a right angle thereto and curving into a storage portion which extends at less than a right angle to said path of movement, a track guide normally extending parallel to said track, said track guide including a portion movable into engagement with at least one fastening device supported on said track, a breaker member mounted for movement toward said track with one end of said breaker member being engageable with a fastener supported on that portion of said track which includes the adjacent ends of the said discharge and storage portions thereof and the curved portion intermediate said adjacent ends, and means for moving said breaker member and said track guide into such engagement during movement of said driver on a driving stroke.

2. Fastener feeding means according to claim 1 wherein said track guide is provided with a tapered end normally positioned adjacent the discharge end of said track and projecting into the path of movement of said driver, said tapered end being movable away from said path with movement of said track guide.

3. Fastener feeding means according to claim 2 fur ther including an adjustable member.carried by a said driving device for defining the normal position of the movable portion of said track guide and the said tapered end thereof.

4; Fastener feeding means according to claim l wherein said driving device is of the pneumatic type includinga cylinder and a piston mounted therein to operate said driver on its driving and return strokes and wherein said means for moving said breaker member and said track guide comprises an auxiliary piston carried by said device with means for actuating said auxiliary piston in response to actuation of said driver operating piston.

5. Fastener feeding means according to claim 4 wherein said auxiliary piston is carried for movement in an-- gular relation to direction of movement of said driver piston.

6. Fastener feeding means according to claim 1 wherein said breaker member is carried by said track guide.

7. A construction for feeding fastening devices into the path of travel of a driving member operable on a driving stroke comprising a track for slidably supporting fastening devices in a row, means for normally urging such fastening devices along said track toward said path of travel, a track guide member, means mounting said guidemember adjacent said track with at least the portion of said guide member adjacent the discharge end of said track being movable toward and away from said track and means operable in synchronism with driving movement of said driving member for moving said guide member toward said track and into clamping engagement with at least one fastening device supported on said track thereby positively interrupting the said normally urged movement of said fastening devices along said track.

8. A construction for feeding fastening devices as set forth in claim 7 further characterized by the end of said track guide member adjacent the discharge end of said track projecting into the said path of travel of said drivin-g member, said track guide end being movable away from said path of travel upon movement of said track guide toward said track.

9. In a device for driving fasteners having a driver operable on a driving stroke to engage and drive a fastenet fed into its path of movement from a fastenermag"- azine,-an improved construction for such magazine comprising a track member adapted to support fasteners in a row, said track having a discharge portion leading into the path of driver movement at approximately a right angle thereto, a storage portion extending at less than a right angle to said path of movement and a curved portion intermediate said discharge and storage portions, a member movably mounted adjacent said track in normally spaced relation therewith, and means for moving said members into clamping engagement with at least one fastening device supported on said track.

10. A fastener driver according to claim 9 wherein the said movably mounted member is positioned to engage a staple supported on said track in the region of transition from the end of the said storage portion thereof to the said curved intermediate portion thereof.

11. A fastener driver according to claim 9 wherein said track is adapted to support U-shaped staples along the crown portion thereof, said movably mounted member being movable from a normal position toward the center of the said curved intermediate track portion into engagement with the crown of a staple supported on said curved intermediate track portion.

12. A construction for feeding fastening devices into the path of travel of a driving member operable on a driving stroke comprising a track for slidably supporting a row of fastening devices, said track having a discharge end portion extending at an angle to the remaining portion thereof and at substantially a right angle to the path of travel of said driving member, a breaker member movable into clamping engagement with a fastening de vice supported on Said track at the intersection of the two said portions thereof, and means for moving said breaker member into and out of such engagement in synchronism with movement of said driving member on its driving and return strokes respectively.

13. In a pneumatic tool for driving fastening devices having a cylinder, a piston and a fastener driver member operable on a driving stroke by said piston to engage and drive a fastener fed into its path of movement from a fastener magazine, an improved construction for such magazine comprising a track member adapted to support fasteners in a row, said track member having a discharge portion leading into the path of movement of said driver member at substantially a right angle thereto and a storage portion extending in angular relation to said discharge portion with the position of said storage portion rlative' to said path of movement being. such as to include a component parallel to said path of movement, means" for normally urging fasteners along said track toward the discharge portion thereof, a track guile member having portions corresponding to the said portions of said track, means supporting said track guide in spaced substantially parallel relation with said track to provide a path for the free movement of said fasteners between said track and track guide, said supporting means being such as to permit the terminal portion of said track guide and a section of the adjacent storage portion thereof to move toward said track into engagement with at least one fastener supported thereon, and means for producing such movement in synchronism with each driving stroke of said driver member.

14. A pneumatic driving tool for fastening devices as set forth in claim 13 wherein said means for producing movement of said track guide comprises an auxiliary piston and cylinder mounted on said tool, said auxiliary piston being operable on a driving stroke in a direction angularly to the said driving stroke of the driver member, means for translating driving movement of said auxiliary piston into movement of said track guide toward said track, and a connecting passage between the head of said auxiliary piston and said main cylinder, said passage being opened to air pressure by movement of said main piston on its driving stroke.

15-. A pneumatic driving tool for fastening devices according to claim 13 wherein said movement of said track guide results in the engagement thereby of at least one fastener supported on the track intermediate the said discharge and storage portions thereof where the track changes direction to establish the said angular relation between said portions.

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